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CobraPower97 04-09-2001 12:27 PM

Gear question
 
I bought a 4.10 gear set for my Cobra and was wondering how the car is for the street. How is the rmp range in 5th gear on the highway? I got a good deal on the gears from a friend they are brand new Richmond gears. Anyone use them?

Thanks

97snakedriver 04-09-2001 12:45 PM

I have 4.10s. They are fine for the street. For the track I would go with something higher (4.30+), but if you do highway driving 4.10s are probably enough.

RPM at 70 is about 2500. I haven't had any loss in milage.

bark3rd 04-09-2001 02:22 PM

Check out the thread titled "is chip needed for 3:73's" for some addtl' info. I have since decided to go for 4:10's myself, they are being installed Wed., I'll let you know how they work out.

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Black 2000 GT,5 spd,17" wheels,mach,leather

T_Bone 04-09-2001 05:29 PM

bark3rd, the difference is he is in a Cobra, you have a GT.
I had 3.73's in my 96GT
I have 4.10's in my 97 Cobra. I'll be changing to 4.56's this summer. Here is a link to an RPM/Speed/Gear calculator.
http://www.corral.net/tech/gearcalc.html

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T-Bones 1997 Cobra
Wht/blk, Pro 5.0,FRPP 4.10's, aluminum driveshaft, FRPP throttle body, C&L 80mm MAF, K&N, Steeda U/D pulleys, Steeda timing adjuster, Flowmasters, s/f connectors, FRPP pro springs, BBK caster/cambers.
http://web.ndak.net/~topel/TBone1.jpg

AutoX281 04-09-2001 07:52 PM

T_Bone: Why does Cobra vs GT make a diff? is it b/c the DOHC can handle the higher rpms better than the SOHC? I don't know much about the cobra engine specs...

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98 GT Conv: K&N, Pro-5.0, MSD wires

CobraPower97 04-10-2001 10:55 AM

So how did the performance improve when you put the 4.10s in? Do you run at the track? What kind of numbers after the gear change?

97snakedriver 04-10-2001 02:08 PM

Quote:

Originally posted by AutoX281:
T_Bone: Why does Cobra vs GT make a diff? is it b/c the DOHC can handle the higher rpms better than the SOHC? I don't know much about the cobra engine specs...


Cobras rev higher and make their power and torque higher in the RPM band. You shift a stock Cobra at 7000 RPMs when racing.

69ergt 04-10-2001 10:05 PM

T_bone,

I have just recently put 3:73 gears in my mustang. It is also a 1996 gt. Were you able to buy gears for the speedometer, or did you use an electronic speed sensor?
If you used gears what size and where can I get a hold of them?

sean

T_Bone 04-13-2001 01:00 AM

69ergt, I used the white 23 tooth speedo gear. I got it from Steeda because Mustangs Unlimited was out of stock. They raped me in shipping charges. Like $8 to ship a little plastic gear the size of your thumb http://www.mustangworks.com/msgboard/rolleyes.gif The gear runs about $20+ s/h.
Good luck!

BTW, my 4.56's are on their way to me, hehe. Can't wait.



[This message has been edited by T_Bone (edited 04-13-2001).]

04-13-2001 02:03 AM

Anything less than 4.56 on a Cobra is just a waste of hard-earned dollars!!!

Even with a blower, nitrous, or turbo, you can run 4.56's, just get 28" tires.

If you want to know why you should run 4.56 in a Cobra, look at my sig.

Later, Jason

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N/A 1997 Cobra

1/8 mile - 7.83 @ 90.08 MPH
1/4 mile - 12.26 @ 114.02 MPH
1.64 60 ft.

96gtToy 04-15-2001 12:09 PM

thanks t_bone. No-one has given me a straight answer about the gear needed for my speedometer.


1996 gt, K&n filter, 373 gears.
sean

T_Bone 04-15-2001 12:16 PM

Quote:

Originally posted by 96gtToy:
thanks t_bone. No-one has given me a straight answer about the gear needed for my speedometer
no problem

95GTS 04-18-2001 10:20 PM

Just a forewarning fellas, the 23 tooth speedo gear is the one to get the speedo closest (though will still be about 5 mph off after 60 mph), BUT it WILL be chewed up (in the GT). It may take a month or two, depending on how much you drive, but the teeth on the 23 tooth speedometer gear DO NOT mesh with the 8 tooth internal drive gear on the GT T45 trans. IF you use speedo and internal drive gears to correct the speedo you need the 21 tooth (red) speedo gear and the 7 tooth internal drive gear. Only problem is there is no 7 tooth internal drive gear made for the GT. Just for the Cobra. The Cobra has different splines in the center of the internal drive gear than the GT has so you can not use the Cobra internal drive gear. I've been thru this already when I had my 3.73s put in and my transmission rebuilt in my 96 GTS, as some of you probably remember. The ONLY way to get the speedo to read correctly is to use a MECHANICAL speedometer compensator. The new 99-up models use the ELECTRONIC speedometer compensator. I had the 21 tooth in my stang because it was the largest one that would fit and mesh with the 8 tooth internal drive gear. Your speedo will still be off, just not as much as with the 18 tooth (yellow) stock speedo gear. It's the best you can do unless you like particles of plastic speedo gear floating in your tranny fluid and constantly replacing the 23 tooth every few months, or just get the mechanical speedo compensator.

With your Cobra, it already has the 7 tooth internal drive gear so with your 4.10s install the 23 tooth speedometer gear. I believe it does mesh with the 7 tooth. If I'm not mistaken 97snakedriver is running this setup and has not had a problem ( I think it's him, anyways).
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1994 Red SVT Lightning #2019

[This message has been edited by 96GTS (edited 04-18-2001).]

97snakedriver 04-19-2001 12:35 AM

Yeah its me. Me and my 23 tooth gear are getting ready to celebrate our 30,000 mile together. The speedo was off by 3 mph@70 and pretty close every where below that.

95GTS 04-19-2001 07:37 PM

I thought it was you. But couldn't quite remember. http://www.mustangworks.com/msgboard/biggrin.gif

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1994 Red SVT Lightning #2019


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